A Canadian Retrospective Chart Review Evaluating Concomitant Methotrexate De-escalation Patterns in Patients with Rheumatoid Arthritis Treated with Biologic or Targeted Synthetic DMARDs

Abstract Introduction Rheumatoid arthritis (RA) guidelines recommend methotrexate (MTX)-anchored therapy with biologic or targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs); however, tolerability issues often lead to non-adherence. Canadian data on MTX tapering and/or withdrawal following b/tsDMARD initiation are minimal. This chart review assessed frequency of MTX tapering or withdrawal following b/tsDMARD initiation and the impact on disease status in Canadian adults with RA. Methods Eligible patients had received MTX for ≥ 3 months before b/tsDMARD initiation. The b/tsDMARD was prescribed continuously for ≥ 18 months. Patients taking > 10 mg/day oral prednisone or equivalent were excluded. Results Eight hundred eighty-nine patients (mean baseline MTX dose 19.0 mg/week) prescribed b/tsDMARDs (tumor necrosis factor inhibitor 52.1%, Janus kinase inhibitor 18.3%, interleukin-6 inhibitor [IL-6i] 11.9%, other 17.7%) were evaluated at 22 Canadian centers. Within 2 years of b/tsDMARD initiation, MTX was tapered in 123 (13.8%) patients and discontinued in 147 (16.5%), most commonly due to planned tapering (36.6%) and patient decision (27.2%), respectively, and most commonly with IL-6i use (34.9%). The MTX dose was unchanged for 582 (65.5%) patients and increased for 37 (4.2%). Missing data limit interpretations of MTX dose effects on some secondary endpoints and challenge the assertion that a disease activity measure–based treat-to-target approach is routinely used in Canadian rheumatology practice. Conclusions Methotrexate tapering or withdrawal occurred in 30.4% of Canadians with RA within 2 years following b/tsDMARD initiation. Baseline disease activity measures were missing from many medical records. However, for patients with baseline assessments, MTX tapering or discontinuation did not worsen disease activity.